永冲电化学腐蚀制备n型多孔硅及其发光性能

采用脉冲电化学腐蚀法，以n型单晶硅为衬底制备多孔硅（n—PS），通过扫描电镜（SEM）、室温500—700nm范围内荧光光谱，系统研究腐蚀时间、占空比和脉冲频率对n-PS的结构形貌和可见光区室温光致发光特性（PL）的影响，结果表明，相比直流电化学腐蚀方法，脉冲腐蚀能获得孔径分布均匀且发光强度更高的多孔硅；随腐蚀时间、占空比和脉冲频率等腐蚀条件的变化，其发光峰位及发光强度均有明显改变；当等效腐蚀时间为30min、占空比为0．5、脉冲频率为10Hz时，制备的n—PS的PL强度较高，发光性能较好。

Preparation and Photoluminescence Properties of N-type Porous Silicon by Pulse Electrochemical Anodization

N-type Porous silicon （n-PS） was prepared on a phosphorus-doped n-type Si wafer by pulse electrochemical anodization. The scanning electron microscopy （SEM） and the photoluminescence （PL） investigation （500~700nm） showed that the formation, structure, morphology and PL performance of n-PS were controllable by experimental conditions, such as equivalent etching time, pulse frequency and pulse duty cycle. The porous silicon prepared by pulse electrochemical etching was more uniform with high PL intensity. The influences of experimental conditions, such as equivalent etching time, pulse frequency and pulse duty cycle on photoluminescence peak and the luminous intensity were obvious. The high luminous intensity and PL performance of PS could he obtained with equivalent etching time of 30rain, pulse duty cycle of 0.5 and pulse frequency of 10Hz.